Abstract
Purpose: Cerebral venous oxygenation (Yv) is an important biomarker for brain diseases. This study aims to develop an R2*-based MR oximetry that can measure cerebral Yv in 3D. Methods: This technique separates blood signal from tissue by velocity-encoding phase contrast and measures the R2* of pure blood by multi-gradient-echo acquisition. The blood R2* was converted to Yv using an R2*-versus-oxygenation (Y) calibration curve, which was obtained by in vitro bovine blood experiments. Reproducibility, sensitivity, validity, and resolution dependence of the technique were evaluated. Results: In vitro R2*-Y calibration plot revealed a strong dependence of blood R2* on oxygenation, with additional dependence on hematocrit. In vivo results demonstrated that the technique can provide a 3D venous oxygenation map that depicts both large sinuses and smaller cortical veins, with venous oxygenation ranging from 57 to 72%. Intrasession coefficient of variation of the measurement was 3.0%. The technique detected an average Yv increase of 10.8% as a result of hyperoxia, which was validated by global oxygenation measurement from T2-Relaxation-Under-Spin-Tagging (TRUST) MRI. Two spatial resolutions, one with an isotropic voxel dimension and the other with a nonisotropic dimension, were tested for full brain coverage. Conclusions: This study demonstrated the feasibility of 3D brain oxygenation mapping without using contrast agent. Magn Reson Med 79:1304–1313, 2018.
Original language | English (US) |
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Pages (from-to) | 1304-1313 |
Number of pages | 10 |
Journal | Magnetic resonance in medicine |
Volume | 79 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2018 |
Keywords
- MR oximetry
- blood R2*
- blood oxygenation
- hyperoxia
- phase contrast
- venogram
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging